Sunday, April 13, 2008

Reading "The Best of All Possible Worlds"

We are a far cry from Plato, for instance, who taught that the objects we observe are but images, or shadows, of originals, the only true and real Objects, which exist in a world above one own, the world of Ideas. [...] Poincaré points out that science does not need that kind of belief: there is no need for objects to exist in any other way than to relate our sensations with common experience. Clearly there is no more room for metaphysics: science can be concerned with relating only facts, not things.

A residual Platonism often confuses natural science, mathematics, and computer science. Time to read Poincaré.

1 comment:

You sent me looking for an old Dover reprint of Science and Hypothesis by Poincaré.

From p 90

"1. There is no absolute space, and we only conceive of relative motion; and yet in most cases mechanical facts are enunciated as if there is an absolute space to which they can be referred.

"2. There is no absolute time. When we say that two periods are equal, the statement has no meaning, and can only acquire a meaning by a convention.

"3. Not only have we no direct intuition of the equality of two periods, but we have not even direct intuition of the simultaneity of two events occurring in two different places. I have explained this in an article entitled, Mesure du Temps,1

"4. Finally, is not our Euclidean geometry in itself only a kind of convention of language? Mechanical facts might be enunciated with reference to a non-Euclidean space which would be less convenient but quite as legitimate as our ordinary space; the enunciation would become more complicated, but it still would be possible.

"Thus, absolute space, absolute time, and even geometry are not conditions which are imposed on mechanics. All these things no more existed before mechanics than the French language can be logically said to have existed before the truths which are expressed in French..."

_____

It is a bit off-subject but I was reminded of Feynman's position on the social sciences, which he considered to be pseudo-science with the potentail of being real (but not now).

After looking trhough some old books for a half hour, I decided to Google and found a video on youtube (!)

About Me

I am VP and Engineering Fellow at Google, where I lead work on natural-language understanding and machine learning. My previous positions include chair of the Computer and Information Science department of the University of Pennsylvania, head of the Machine Learning and Information Retrieval department at AT&T Labs, and research and management positions at SRI International. I received a Ph.D. in Artificial Intelligence from the University of Edinburgh in 1982, and I have over 120 research publications on computational linguistics, machine learning, bioinformatics, speech recognition, and logic programming, as well as several patents. I was elected AAAI Fellow in 1991 for contributions to computational linguistics and logic programming, ACM Fellow in 2010 for contributions to machine-learning models of natural language and biological sequences, and ACL Fellow in 2017 for contributions to sequence modeling, finite-state methods, and dependency and deductive parsing. I was president of the Association for Computational Linguistics in 1993.